(a) Field
The invention relates to a display device and a driving method of the display device. More particularly, the invention relates to a method for effectively reducing luminance imbalance of a display device due to a voltage drop of the display device using an organic light emitting diode.
(b) Description of the Related Art
In recent years, various flat panel displays capable of effectively reducing weight and volume which are demerits of a cathode ray tube have been developed. The flat panel displays include a liquid crystal display (“LCD”), a field emission display (“FED”), a plasma display panel (“PDP”), and an organic light emitting diode (“OLED”) display.
Among the flat panel displays, the OLED display, which displays an image using an OLED generating light by recombination of electrons and holes, is driven at low power consumption while having a rapid response speed and is excellent in emission efficiency, luminance, and viewing angle.
In general, a plurality of pixels emitting light in the OLED displays include OLEDs, and each OLED emits light with predetermined luminance corresponding to a data current supplied from a pixel circuit.
As one gray expression method of an OLED display, digital driving controls time during which an OLED of a pixel is turned on. In an OLED display emitting light using the digital driving method, one frame is divided into a plurality of sub-frames, and a light emission period of each sub-frame is appropriately set for gray expression. Pixels emit light during a sub-frame selected according to an image signal for gray expression among a plurality of sub-frames that forms one frame.